Mobile telephone simulator study

• The study consists of four separate experiments conducted in the VTI drivingsimulator. The common theme was to investigate how driver behaviour andtraffic safety are influenced when the driver attends to another technicaldevice while driving. The experiments were concerned with handsfree orhandheld mobile phone conversation and dialling, receiving mobile phone SMSmessages and watching a DVD film (the latter two being minor pilotexperiments). In three of the experiments (mobile phone conversation, SMS,DVD) the participants drove a route which led through urban and ruralenvironments, ranging from 90 km/h rural to 50 km/h urban environments. Theurban environments differed in complexity (three levels). The drivingdistance was about 70 km. The dialling experiment used a rural environmentwith a speed limit of 110 km/h. The driving distance was about 15 km. In themain experiment dealing with mobile phone conversation, a number of drivingperformance measures were analysed: driving speed, variation in lateralposition, deceleration, brake reaction time, headway, time to collision, etc.PDT (Peripheral Detection Task) was used as a measure of mental workload.Mobile phone conversation was found demanding in terms of mental workload. Italso had effects on driving. Most effects were quite similar for the twophone modes (handsfree, handheld). Impaired reaction time performance wasdemonstrated in one of the situations for handheld mode. However, effectswere found which could be interpreted as attempts to compensate for theincreased workload caused by the mobile phone conversation: speed was reduced(more so for handheld than for handsfree mode), and time and distance headwayincreased. In spite of these compensatory behaviours, mental workload wasstill markedly increased by phone use. In the SMS experiment the participantsbraked later in one situation when reading the SMS message. No other effectswere found in this minor experiment. In the DVD experiment, mental workloadincreased when watching the film, although this was compensated for to someextent by the increased distance headway to a lead vehicle. No compensationin terms of reduced driving speed, however, was apparent in this experiment.In the dialling experiment negative effects on traffic safety were evidentfrom the larger variance of lateral car position during the dialling task forthe handsfree phone mode. The mental workload also increased with thedialling task. Compensation in terms of reduced driving speed was apparentfor both phone modes. Other aspects of mobile phone use while driving stillremain to be analysed in more detail, such as starting or finishing a call,looking for a phone number to dial, mishaps like dropping the phone, etc.

Nyckelord

English

Sweden

Mobile

Telephone

Driving

Simulator

Driver

Behaviour

Attention

Driving aptitude

Stress

Safety

Road: Road user behaviour

Road: Road user behaviour

Publikations- och innehållstyp

vet (ämneskategori)

rap (ämneskategori)